1. Field of the Invention
The invention relates to a blower for air conditioner of automotive vehicles, more particularly, to a blower for air conditioner of automotive vehicles, which is capable of striving to increase the blowing volume and reduce noise, and simplifying the structure of the blower by distributing the air come into the inside of an intake duct effectively to an upper blowing wheel and a lower blowing wheel in the field of the blower with a double suction type centrifugal fan.
2. Background Art
The vehicle air conditioning device comprises a cooling system for cooling the indoor of a vehicle, and a heating system for heating the indoor of the vehicle. The cooling system is constructed that the indoor of the vehicle is cooled by emitting the blowing air into the indoor of the vehicle after it is changed into cold air by means of the heat exchange between the cooling medium circulating from a condenser to a compressor via a receiver drier, an expansion valve, and an evaporator, by the driving of the compressor, and the blowing air passing through the surface of the evaporator by the blower. Also, the heating system is constructed that the indoor of the vehicle is heated by the heat exchange between the cooling water passing through a heater core and the blowing air.
The blower is connected to an inlet of a case for an air conditioning device, in which the evaporator of the cooling system and the heater core of the heating system are built-in, to thereby blow the inside air or outside air to the inside of the case of the air conditioning device.
In other words, as shown in FIG. 1 and FIG. 2, the conventional blower comprises a scroll case 10 formed with a discharge opening 14 at one side to be connected to a case of the air conditioning device (not shown), and its upper portion opened; an intake duct 30 mounted at the upper portion of the scroll case, and equipped with at least one of the inside/outside air suction openings 32, 34 and an intake door 36 for converting the opening degree of at least one of the inside/outside air suction openings 32, 34; a suction opening 20 for forming an air suction passage between the intake duct 30 and the scroll case 10; a centrifugal fan 40 mounted rotatably at the scroll case 10; and a motor 50 connected to the centrifugal fan 40 through the lower portion of the scroll case 10 to rotate it. The reference numeral 60 in FIG. 1 denotes an air filter for filtering foreign substance contained in the air sucked into the intake duct 30, and the air filter 60 can be selectively mounted.
The centrifugal fan 40 is a single suction type, and is constructed to suck air through one side of the axial direction, that is, it is constructed to suck the air through the suction opening 20 according to the rotation of the fan and emits it in the radial direction. In other words, the centrifugal fan 40 comprises a hub plate 42 connected to an upper end of a shaft 52 of the motor 50, a plurality of blades 44 disposed in radial direction along the upper edge of the hub plate 42, a supporting ring 46 connected and supporting upper ends of the blades 44. Also, the hub plate 42 is conventionally formed to depress toward the inside (that is, upper side) of a space defined by the blades 44, so that a portion of the motor 50 is connected to the hub plate 42 with inserted into the inside of the space.
Accordingly, when the centrifugal fan 40 is rotated by the driving of the motor 50, the inside air or the outside air can flow in the axial direction of the centrifugal fan 40 through the suction opening 20, through the inside air suction opening 32 or outside air suction opening 34, which are selectively opened according to the control of the opening degree of the intake door 36, to thereby flow along the slanting upper surface of the hub plate 42 to be discharged in the radial direction of the centrifugal fan 40. Thus, the air flows along the side wall of the scroll case 10 and is ventilated into the inside of an air conditioning case (not shown) through a discharge opening 14 with increased blowing pressure and blowing volume.
However, with regard to the blower with a single suction type centrifugal fan 40, when the air is emitted from the centrifugal fan 40 in the radial direction, as shown in FIG. 1, there occurs a problem that flow dispense of the air in the upper/lower portions is not even because the air is emitted along the slanting surface of the hub plate 42.
Furthermore, as shown in FIG. 2, if the structure of the air flow at a portion, where a scroll portion 12 of the scroll case 10 and the discharge opening 14 meet, that is, at a cut-off region 16, is to be reviewed, the air emitted from the centrifugal fan 40 in the radial direction and flowing directly into the discharge opening 14 collides with the air emitted from the centrifugal fan 40 in the radial direction to flow along the side wall of the scroll portion 12 at the cut-off region 16 thereby to be mixed to produce turbulent flow. Thus, when the air flow dispense is not even and the turbulent flow is generated, there also occurs a problem of the reduction of the blowing volume and the increase of the noise.
To solve such problems arising in the conventional blower with a single suction type centrifugal fan, there is suggested a double suction type blower capable of sucking and emitting the air from both directions, so that it is possible to increase the blowing volume, reduce noise, and induce two layer air flowing.
As one example for such a double suction type blower, there is disclosed a Japanese patent application laid open No. 200-309216, in which a motor is engaged with two single suction type blowing wheels connected to each other in the opposite direction. However, according to such conventional technology, the size of the blower becomes large, the number of parts thereof increases, and the number of assembly work increases to thereby increase the production cost of the blower.
Another example of such a double suction type blower is disclosed in Japanese utility model application laid open No. Hei 05-10016. Such blower comprises, as shown in FIG. 3, a scroll case formed with upper/lower suction openings 112, 114 at upper/lower surfaces and a discharge opening (not shown) at one side; a double suction type centrifugal fan 120 mounted rotatably at the scroll case 110 with the upper/lower blowing wheels 122, 124 formed integrally with a hub plate 126 in the direction opposing to each other; an intake duct 140 with an outside air suction opening 142, a plurality of inside air suction openings 144, and a plurality of (four) intake doors 146 for controlling the opening degree of the suction openings 142, 144, and forming air passages 150, 152 for distributing the air to the upper/lower suction openings 112, 114; and a motor 130 connected to the hub plate 126 via the lower suction opening 114 to rotate the double suction type centrifugal fan 120.
According to the blower shown in FIG. 3, when the outside air suction mode is operated, the outside air is dispensed and sucked toward the upper/lower suction openings 112, 114 with all the inside air suction openings 144 closed and only the outside air suction opening 142 opened. Also, when the inside air suction mode is operated, the inside air is dispensed and sucked toward the upper/lower suction openings 112, 114 with the outside air suction openings 142 closed and all the inside air suction opening 144 opened. Furthermore, when the inside/outside air suction mode is operated, the inside/outside air is mixed and sucked toward the upper suction opening 112, and the inside air is sucked toward the lower suction opening 114, with a portion of the outside air suction opening 142 opened and a portion of the inside air suction openings 144 selectively opened.
However, with regard to the example shown in FIG. 3, especially, when the inside air suction mode is operated, the dispense of the air toward the upper/lower suction openings 112, 114 is not performed effectively, so that it is required to form a plurality of inside air suction openings 144 and a plurality of intake doors 146 to solve such problem. Also, there occur problems that the size of the blower should be increased, the mounting space for the blower with regard to the vehicle should be increased, and the structure of the driving means such as a lever mechanism (not shown) for actuating the intake doors 146, and the like becomes complex, because a portion of the intake doors 146 is constructed such that inside air suction openings 144 are configured to be opened toward the outside of the blower. In addition, with regard to the blower shown in FIG. 3, water or foreign substance can be concentrated at the bottom of the intake duct 140, that is, at the lower of the motor 130, to thereby cause disorder of the motor 130 or mis-operation of the motor 130.